Combined reproduction and sending unit



sept. 22, 1931.V C. BURK 1,824,655

COMBINED REPRODUCTION AND SENDING UNIT Filed May 29. 1929 3 Sheets-Sheet l INVENTOR. CZarerzceEBz/,rg

Sept. 22, 1931. C, E- ---BURK' 1,824,655

COMBINED REPRODUCTION AND SENDING UNIT Filed May 29. 1929 3 sheetsfsneet 2 lf'zZ.

. if if e-' l E ,/"8

No. nnmnmnnmi ,60 466 INVENTOR.

67 A TTORNEY.

Sept. 22,11931. c. E. BURK 1,824,655

COMBINED REPRODUCTION AND SENDING UNIT Filed May 29, 1929 3 Sheets-Sheet 3 6'7 59 53@- u-u es JQ'\`O L---fji@M"Q5 IN VEN TOR.

Patented Sept.` 22,1931 f *i lf3-fu j This inventionrelates toa combined repro;l Figure; 2 is a front elevation: of thegun'itvv duction and sending unit ora radio receiver, kvvitlithe front'of the cabinet' removed.fY address system and record Yreprodufotonjand lFigiire' ijs affront elevation ofthecabiff e has for its object to provide; in manner as net Vyvheiiclosed. v p

5 hereinafter setforth a` unit of and combining Figureli is'y a rear' elevation of thefrkctbb w in a single cabineta radiqreeeiveigjopower riet.. l I v p y .n y amplifier, ai microphone input .'amp1iiier,- av Figure 5 is en elevation looking {30m-birdsj coii'trollingmeans for selectivelyyettingfiii, one end of tlie cabinet. t. l Y one or more Ioud speaker circuits with respect l Figure 6 is anV elevation-`1ook1ngtowards tol the power amplifier anda vcont/rolling the ,other lendpf 3511.3 @Ahmet l, means common to a record pickup, thera--jl Referrmgto. Figure l 'of the drawings vl dioreceiver andthe microphone input amplis", p indicates aradiotiiiier or recelyeset for tun', Iier for selectively cutting infoiie; of sii'cll'i nig in' radio programs, Qindieates a record s elements with respect fo 'the power amplifier; f pick im which is attachedtoje phonograph, v3Q r 'A further objectof-the invention is to" ro#A designates e microphone inpiit amphier; for 6e vde. in a. manne-r as'hereinafter set fortlya* amplifyl'ng tlie'signlof a microphone 4,`t lie unitl'of the class referredto inchidingaJ-ra-S latter-being in theforin of a; desk transmit-' dio receiver, a mierophoneinpnt ampli er and ter microphone.j switch or ,controller4 key a power amplifier honsed in a normally looked 1S Indicated at 5 and Winch4 is common t9 and 2G cabiiet-fwhereby it is "impossible to operate;k 311191957661k for Cutting in the output from kthe .70 the receiver withoutfnnlocking the :cabinet Ieevlvevrpl, recordpiieknp 2 andmlcrolholel under such conditionsl'preventingthefopera l tvthepo'wer amplifier 6l which is associated tion of the unit by one notatit'horzed. mi Wlfh a 'Serres' 0f 1911@ "Srgeret'lnf:YIS 7.` A ,bank olf;

Further objects of the inventionv are to pro! keys or switches is indicated at- Sxand'is om; vide,viii amannera-s hereinaftensetffortliia Proyed forselectlvely lCOU'OHHIR' th-IU w unit of the class referred `to -Which is simple SUGlkI'SI 7 Witlixresp'ect to the'nmplierj, S0

in its construction and arrangement strong, I??? Qinioregpahll .gcher lpnld gpakers durable, compact, thoroughly ericientin its "Ca'lLIg my V51 Qmlyesitiiiifi mecus y. use, conveniently operated, readily assembled 11,1111? Strpl 71H ICQ?, at, all 1S Qrflpqye and comparatively inexpensive to,iiictiiufac 01 Connecting the speaker keys or switches to eo ture. w "if lfy ff f j Cqnductorsflo'leadingtothe loud speakers?.

With the foregoing` aiidotlierfobectsiri GIICUIlfi CTIDQCIOHSSQledfqm .thQSJYIlChes view, the inventionvconsists ofa novel ,con-` 8"@0, Cd@ telcmtllal SIIp T plrolidspeakers ..structomombiniion O and arrari enlilentdof. grbteof (nljteintdlf 875: parts as @reina er'moie speci Ca. y*Y x3- Y J- y' l y M h` @be and @the meer@ digerir-erde.faireessere? dfamgwhefemlsehow anembocrrmeef'fef c :in er fCeVIf-fi le 1 in? im fe-mese ce. 'missions pa ses foresee 4U ChangesWMP10@andfmdlcmons Cafbe line 14;? The-'switch ii is escorted with che" v0 resfrred t0 Whrch fauwrthmftre-@OPG th? receiver "Switch li2 with the microphone inv`r clalmshereunw appended' v 'Y Vptit simplifier `3 'and sfijvitchl 13 with the povver: I fthe drawlrgs f ,rherem 1.11 refer amplifier e. Aucune:- is indicated at' 15 @me Characters denotes sofeswndmg Perte which fs interposed infile power uns i4. thrqlrghout the Seifvefad View?? I 'Y ljcfil `svvitch 8 has as a partthereof a vresist; 95 F 11g-'Ur e S a (rrag'rammatcrvlew luustraf aricl 'Connected when' the eircuit'is'opening the' Circuit arrangement When the H1111? 15?' to keep the circuit balanced atallf timesand.; installed with respect to' a radio receiver,"an the mpefdraricev ofall tlieqeireiiits balanced-1 .f 'ductors 19, 20V lead from conductors 28, 29 lead :trom the.,S,Witch from the microphone-4 are plugged in the The-outer portion oftheV Yto switch, 11k to the receiver 1. Circuit conthe switch 12 to the microphone input amplifier 3. Circuitconnections 21, including inner and outer portions, lead from the microphone to the input amplifier 3. Circuit conductors 22, 23 lead from the switch 13-tothe -power amplifier 6. Circuit conductors24, 25 lead frornthe out-v let 15 to the switch 11; Circuit conductors 26, 27 lead VJfrom. the switch 12 to the cirf cuit conductors 24, 25 respectively. Circuit left hand end 4() providedwith .a connector plate 42 and itsgright handY end 43 with a The 'cabinet 41 has inf stalled therewith the Aradio receiver 1 the;

connector plate 44.

lmicrophone input amplifier 3, the power ampliier, the switch 5,switches 11, 12 and 13, thebankof. keys or switches-'8, the outlet 15-microphone 4,y circuitfconnections, 39a, in-v` ner portion of circuit connections 21 .which-are attached'to'connector plate 42 andzinnerfpor-j ytion of circuitconnections 30,v 31 whichl are The powerl attached to Vconnector plate44. l line 14 is connectedto the-outlet 15.*, Theouter portion of the circuit connections 21leading connector plate 42.. y circuit connections 30, 31 leading -fromr the record pick up 2 are plugged in theconnector plate 44. The circuitconnections 'orwiresld whichl lead Lto the loud speakers7f-project from the strip 9which :is arrangedat the back of the cabinet.` isindicated at 45. fThe outlet 1 5 is -C'OIlItected-l The kback-oi1 the cabinet 41 tothe back of the cabinet.- 4

The circuit connections117, 18,-' 19,` 20,. 22, 23, 24, 25,26,

38, 39, areflnstalled within thev cabinet 41. f

' VEachlend of cabinet 41 ,has la narrow por-y tion/46 and a wide portion 171,47 to provide a shoulder tion 46 and the latter extendsupwardly from the portion '47., The rearl edges of .the-pon. The back of Vthe cabinetcomprisesan upper por--Y tionsf40, 46 are iush with v each other.

tion`49, an1 intermediate portion50 andf'a `lower portion 51 thelatterbeing of greater height than the other portions o :the back.

'.1`helower/portion 51 consists ofa frame hav,-r mg theorems -erovdedihereba Clase/expr' 1 as vat `59`t provide a vent 13 to` lead frornthe recrd pick Vup 6 and circuit conductorsv 1. thereof isa front 4 8 which-projects ,forwardly of. ,the narrow 4portion 46'. The wide portion 47 1sl ofgreaterv height-than the narrow pora reticulated panel 52. The upper portion 49 is provided with openings 53, 54 or'the passage of antenna and ground leads 55, 56 respectively. The strip 9 is secured to the intermediate portion of the back 45.

The cabinet Jfurther includes a top 57 which seats Lupon the top edres of the portions 46 ofthe ends of the cabinet. The top.57 is hinged to the portion 49 of the .back 50, as at 58. The portion 49 of back 45 is notched i opening. The top 57 projects laterallyfrom the portions 46 of "the ends of the cabinet'and also from the front edges ofthe portions 46.

Secured'upon the shoulders 48 formed by the .top .edges of the portions 47 at the'ends of thecabinet 41 is aboard 60providing a platform or a deskand which projects forkwardly from the front edges of the portion 470i the ends ofy the cabinet. V

Arranged between the portions 46 vof the ends of the cabinet and projecting above the rearof lthe desk 60 is a closure strip 61 which is flush withlthe rontedges of the portions 46. Y i Positioned', upon., the top edge of the str ipl, andiarranged between the portions 46: and the ends ofthe cabinet-isv a sill memfber62L carrying the-switches 1-1,` 12 and 13.

Arranged within ,the cabinet 41 between the sillrnember 62 and top 57 is the receiving set1..v Hinged tothe.; portions 46 of the ends of the 4 cabinetareA doors6`3, 64 which when closed are interposed between the top 57 V'portions 46 andthe sill membery 62. The doors when closed are adaptedto-be locked and ,al

lock orsuch purpose is indicated katf65. The bank of gkeys or switches desk 60vfin`fproximity tothe closure strip 61.

rIhe microphone 4-is supported by desk 60.

The switch-5 is carried by the platform 60 in proximity to, one end thereof. v

lArranged between the portionsl 47 ofthe end sQofthecabinet and iushwith the shoulders ,48.,andxthe front edgesgof portions47 is a front closure strip V66 or suitable height and which is lixedly secured. in position. Secured between theportions 470i the ends of the cabinet and 4flush with thebottornj edges ofsuch portions,fas well as the front edges closure lstrip 67 of approj lntlerposed.4 between the strips 66,67 and'hinged as at 68 to the portions 47 o'ttheends of the 'cabinet is a pair of'fdoors 69, '2'0 for' closingtheflower portion ofthe ront'o'f the cabinet. When the doors 69,70 are in closed 4position they are locked insuch position andthe lock for such purpose is indicatedfat 71.l -That portion of the cabinet 41 below desk 60 provides a chamber priate height.

-72 intoigfa pair ofcompartmentsV 73, 74.

8 are carried by the Mounted on the-partition n72 is-the power arnp lirfier g6 supported, within the compartment .7 4 is the microphone inputampliiier.

The cabinet is normally locked and the unit cannot be made active until the cabinet is unlocked. A v

The switch 5 is of such type that when the handle thereof is in a perpendicular position the receiver 1 is connected to the power amplifier 6 and the radio program from the re-` ceiver can be sent to the loud speakers.` When thek switch 12 is closed the microphone input amplifier can be connected to the power amplifier 6 by shifting the handle of switch 5 forwardly and one can then talk through the unit to any or all of the loud speakers. It being assumed that one or all of the switches may be closed. Switch 11 is closed when receiver 1 is connected to the power amplifier 6. Switch 13 is closed when the power amplifier 6 is to be active. When the handle of the switch 5 is pushed backward the record pick up is connected with the power amplifier 6. When the handle of any of the switches 8 is perpendicular the speaker circuit is open and the resistance cut in, when the switch handle is pushed back the vspeaker circuit is closed. When the record pick up is cut in music or voice therefrom is sent to any one or all the loud speakers, depending upon the number of switches 8 which is or are shifted to close a circuit or circuits.

It is thought that the many advantages of a reproduction sending unit in accordance with this invention and for the purpose set plifier, a power amplifier, means for selec-v tively cutting in said set, input amplifier to a power circuit and power amplifier, a record pick-up, normally open circuits leading respectively from said pick-up, set and input amplifier to said power amplifier, and controlling means common to said normally open pick-up, set and input amplier circuits for selectively closing them to said power amplifier, of a plurality of independent, normally open and selectively closable loud speaker circuits leading from said power amplifier, each circuit including a switch for selectively closing it, each switch having as a part thereof a resistance connected when the circuit is open to keep the circuit balanced at all times and the impedance of all the circuits balanced at all times, and a combined supporting and enclosing cabinet common to said set, transmitter, amplifiers, circuit connections and circuits, said controlling means and switches being located on aswitchboard at the front of the cabinet. f

2. In a centralized switch board control and impedance matching system for reproduction and sending units, a transmitter, an input amplifier in circuit therewith, means for cutting in a power line to said amplifier, a power amc plifier normally open to said input amplifier, means for cutting in said input amplifier to said power amplifier, means for cutting in a power line to said power amplifier, and a plurality of independent, normally open and selectively closable loud speaker circuits leading from said power amplier, each circuit including a switch for selectively closing it,

each' switch having as a part thereof a resistance connected when the circuit is open to Ycircuit with said transmitter, means for selectively cutting in said set and amplifier to a power line, a power amplifier normally ropen to said input amplifier, means for selectively 'cutting in said set and input amplifier to said power amplifier, means for cutting in said power amplifier to a power line, and a pluralityof independent, normally open and selectively closabley loud speaker circuits leadingV from said power amplifier, each circuit including a switch for selectively closing it, each switch havlng as a part'thereof a resistance connected when the circuit 1s open to keep the circuit balanced at all times and the impedance of all the circuits balanced at all times.

4. In a centralized switch board control and impedance matching system for reproduction and sending units, a transmitter, an input amplifier in circuit with said transmitter, means for cutting in said amplifier to a power line, a record pick-up, a power amplifier normally open to said input amplifier and pick-up, means for cutting in said input amplifier and pick-up to said power amplifier, means for cutting in a power line to said 'f-i' power amplifier, and al plurality of independent, normally open and selectively closable loud speaker circuits leading from said power amplifier, each circuit including a switch for A,

selectively closing it, each switch having as a c part thereof a. resistance connected when the circuit is open to keep the circuit balanced at all times and the impedance of all the circuits balanced at all times.y

In testimony whereof, I afliX my signature 

